The present invention relates to a moving apparatus for a detecting arm with a detecting sensor at a forward end thereof , which is movable between a housing position disposed at a position where a processing work is not obstructed and a detecting position projecting from the housing position.
Heretofore, in a moving apparatus wherein a rotating portion is provided at a base end, for example, as disclosed in Japanese Patent Publication (KOKOKU) Sho 62-32071, a rotating shaft 4 of a detecting arm 8 with a detecting device main frame 9 at a forward end thereof is mounted on bearings 5, 6 of a headstock 1 so that the detecting arm 8 can be rotated. The detecting arm 8 is stopped by abutting against a lower limit stopper 18 at a rotation lower limit detecting position where a tool edge of a cutting tool set on a tool rest T abuts against a detecting head 12 or the like of the detecting device 9.
Although the lower limit detecting position of the detecting device 9 at the forward end of the detecting arm 8 is determined by the rotating shaft 4 and the lower limit stopper 18, due to the influence of a clearance of a bearing between the rotating shaft 4 and the bearings 5, 6, there has been a problem such that positioning accuracy of the lower limit detecting position of the detecting device 9 becomes bad.
The present invention has been made in view of the above defect, and an object of the invention is to provide a moving apparatus of an arm for a tool edge sensor, wherein a positioning error due to the moving apparatus at the time of positioning the arm at a detecting position is not created.
Another object of the invention is to provide a moving apparatus of an arm for a tool edge sensor as stated above, wherein the positioning accuracy, especially, iterative positioning accuracy is extremely high.
Further objects and advantages of the invention will be apparent from the following description of the invention.